You can now use claude-sonnet-5 with high effort and automatic thinking switched on by default. The high effort option is now labelled Recommended instead of Default. Admins can use the new managed setting allowedProviders to limit which API providers Claude Code may run on. Setting CLAUDE_CODE_DISABLE_WEB_FETCH turns off WebFetch, the tool Claude uses to download web pages. Claude Code can now load relevant memories saved to your account before a turn. The new claude plugin configure command shows a plugin's options and can save values piped in as JSON.
Seven changes are in the build but not switched on yet. A new plugin test command runs a mod's tests and is marked as early access. Waking and retrying background MCP tasks now sits behind a remote switch that is off by default. A report-delivering tool can end the agent's turn, but only when a server switch allows it. The precomputeCompactionEnabled setting still stays hidden unless a server switch turns it on.
Directory sync for cloud sessions is now fully removed. The CLAUDE_CODE_DIR_SYNC_* variables and CLAUDE_CODE_DISABLE_DIR_SYNC no longer do anything. Launching with --cloud no longer offers to sync your folder, and bundle upload still works. On macOS and Linux, CLAUDE_CODE_LEGACY_BUNDLE is now ignored with a warning. Passing unrestrictedPaths to the agent toolset now throws an error. An @-mentioned audio file no longer gets turned into a transcript for Claude.
Written by our agent from the shipped bundle, not by Anthropic.
New ui_* messages let desktop, mobile and VS Code surfaces attach to a session and draw plugin UI, and a gated list_directory request is added
ExtensionsNew claude plugin configure, plugin install --config reaching bundled MCP server settings, and plugin list --data-size for scripts
claude --desktop opens a session in the Claude Desktop appThe new --desktop flag opens Claude Desktop instead of the terminal, and can pick a session with --continue or --resume <id>
ElsewhereThe new managed setting allowedProviders lists the API providers allowed, and Claude Code refuses to run on any other
Claude Code now handles an mcp.connect request that takes the name of an MCP server
plugin test command runs a mod's testsExtensionsWant the reasoning? Read walks the 34 entries that probably matter to you, each one opening to what changed and why.
Read this release → Every row →2 more of these are in What probably matters to you, on page 1.
When Claude Code resumes an interrupted turn after a worker restart, cleanup of leftover background task notices is now timed and logged
Unclear The new time limit for this step is not known.
Waiting background-task notifications are now merged into the same batch as other checked-for events, sorted by time
Unclear Under what conditions this merging applies is not clear.
Requests from the AWS client now carry the name AnthropicAws/JS, and it keeps a list of AWS profile sign-in keys
Unclear How the list of profile setting names is used is not known.
When connecting to Amazon Bedrock, Claude Code now passes a different API key value and explicitly sends no separate auth token
Unclear It is not clear which setting the API key now comes from, or whether sign-in with AWS_BEARER_TOKEN_BEDROCK behaves differently.
Claude Code now reads CLAUDE_CODE_RESULT_NONCE once at startup, keeps it, and removes it from the environment
Unclear What sets this variable and what uses the stored value are not known.
A check on environment variable names now excludes ANTHROPIC_UNIX_SOCKET and AWS_ENDPOINT_URL names, and includes CLAUDE_CODE_API_BASE_URL only for files
Unclear What this check controls, for example whether it decides which variables are passed on or hidden, is not clear.
Hook prompts are now handled like prompt suggestions and summaries, and a plan-session error message is shown in a different way
Unclear It is not clear what that shared handling of background prompts controls.
Messages from hooks that run when a session starts are now inserted into the conversation individually instead of by rebuilding the whole list
Unclear It is not clear whether anything looks different to a user.
Before its usual permission checks for reading and writing files, Claude Code now runs an extra check that can return a result early
Unclear What the new check tests and when it applies to reads is not clear.
When a permission answer no longer matches a waiting request, Claude Code now records the reason it was dropped
Each plugin sync now records whether your account's plugin list was returned or refused
Unclear What uses this record, and whether you see any difference, is not known.
The list of parts a plugin can contain now names workflows explicitly
Unclear It is not clear whether workflows were already on the shared list, so plugins may have supported them before.
Claude Code now treats remote control as blocked by organization policy only when the denial is final and the policy disallows it with markers present
Unclear What uses this check, what the markers are, and whether an oddly valued remote default nearby is related is not clear.
Messages between Remote Control peers now label the local side "device" instead of "laptop", so mixed versions may not connect
Unclear It is not clear whether the other side of the connection was updated to match.
The reply to a program's opening connection can now list the capabilities already known at that point, so it need not wait for the first turn
In the SDK, the maxTurns value is now normalized before use, and errors from turns that end without the model are tracked
Unclear It is not clear how maxTurns values are changed by normalizing, or how the tracked errors show up in SDK output.
When several tools run at the same time, their updates to the conversation context are now applied once all of them have finished
Unclear It is not clear whether this changes anything you can see.
Claude Code now records the name of the shell tool it is serving when it works out the tool budget
Unclear It is not clear what the recorded shell tool name is used for.
When the check of a web address against the blocklist fails, Claude Code now records the HTTP status code it got back
Claude Code now has named records for each reason a WebFetch source check can be denied, time out or be skipped
Unclear It is not clear whether the web page source check is live.
Workflow runs now carry a marker for reviews launched from an account, tied to BUGHUNTER_RESULT_RELAY
Unclear What this marker changes for a user, and how BUGHUNTER_RESULT_RELAY is set, are both unclear.
Saved workflow references now record whether their session was a review or something else
Unclear What this recorded origin is used for is not stated.
Progress updates for tool calls made inside the REPL tool are removed from the SDK stream, subagent activity and background sessions
Unclear Whether the REPL tool itself still ships is not settled.
Launching with --cloud no longer runs the folder sync offer, local-change check or upload planning, and a new warning covers failed look-ups
Unclear It is not clear whether the folder sync feature was removed or moved elsewhere in Claude Code.
Claude Code's handling of pasted content no longer treats audio specially; only images keep their own handling
Unclear Whether pasting audio was ever something a user could do is not clear.
Claude Code no longer carries an alternative Edit tool description that told Claude to read files outside the working folder before editing them
Unclear The standard Edit description did not change, so it is unclear which setups ever saw the wording that was removed.
The summary of a message's attachments now lists only images, where before it listed images and audio
Unclear It is not clear what this summary is used for or whether audio is still handled somewhere else.
Claude Code no longer treats Audio #N as a pasted-content placeholder; pasted text, image and truncated text placeholders remain
Unclear It is not clear whether pasting audio was ever available to users.
Published verbatim by Anthropic for v2.1.285. Text is unmodified from the upstream changelog. Everything else on this page came out of the bundle instead, which is why the two lists don't match.
Of these 136 bullets, 40 name something an entry on this page also names, 29 name something no entry here does, and 67 name nothing specific enough to line up either way. The pairings are made on names both sides wrote down, a flag or a setting or a slash command, so read one as probably the same thing rather than as a fact, and read the middle number as candidates rather than as a miss count.
CLAUDE_CODE_DISABLE_WEB_FETCH environment variable to turn off the WebFetch tool
Probably new-host-env-var-claude-code-host-prompt-supersedes-record-a, new-claude-code-disable-web-fetch-env-var-turns-off-the-webf claude --desktop to open the Claude desktop app on the current directory, or on a session with --continue / --resume <id>
Probably wide-ranging-desktop-option-rejects-subcommands-claude, update-refusal-message-names-the-two-directories, resume-of-a-live-session-now-hands-off-with-a-prompt, new-claude-desktop-launcher-for-claude-desktop, new-desktop-cli-option, resume-picker-now-offers-to-open-a-live-background-session, desktop-flag-rejected-when-combined-with-background-or-wor, resuming-a-live-background-session-can-now-attach-to-it-and claude plugin configure <plugin> to show a plugin's options and which are unset, or save new values read from stdin with --values-stdin
Probably new-claude-plugin-configure-cli-command-with-values-stdi <server>.<key>=<value> to claude plugin install --config, so a bundled .mcpb MCP server's own settings can be set at install time and it starts without visiting /plugin → Configure
Probably hint-for-bundled-mcp-servers-that-need-configuration, config-keyvalue-parser, mcp-server-policy-checks-extended-to-plugin-provided-and-url, plugin-install-config-reaches-bundled-mcp-server-config, new-claude-plugin-configure-cli-command-with-values-stdi, config-accepts-bundled-mcpb-server-fields allowedProviders managed setting to limit which API providers a machine may use (Anthropic API, a custom endpoint, Bedrock, Mantle, Vertex AI, Foundry, Claude Platform on AWS, or a Cloud gateway)
Probably managed-policy-read-failure-message, login-screen-honours-allowedproviders-managed-setting, wide-ranging-desktop-option-rejects-subcommands-claude, claude-authenticate-joins-an-in-flight-oauth-flow-and-enfo, managed-settings-helper-merge-doc-allowedproviders-is-a-w, settings-validation-for-allowedproviders, provider-not-allowed-startup-refusal, allowedproviders-managed-setting-restricts-which-api-provide, allowedproviders-policy-enforced-on-login-and-setup-token CLAUDE_CODE_NONSTREAMING_TIMEOUT_RETRIES environment variable to cap re-sends of a non-streaming fallback request that timed out
No entry names this claude -p with CLAUDE_CODE_FORK_SUBAGENT=1: a subagent's own Agent call now runs in the foreground, so the subagent gets the child's result
No entry names this GIT_SSH or in your git config's core.sshCommand
Probably plugin-git-clones-now-read-coresshcommand-and-sshvariant, git-ssh-handling-reworked-for-vetted-clones claude plugin disable and enable with a full name@marketplace id changing a settings entry in another letter case instead of the installed plugin's own
No entry names this set_model request (such as the Agent SDK's setModel) leaving the new model on the built-in output-token limit and auto-compact window until restart
No entry names this @, or all of it when the URL writes its @ as %40
No entry names this /teleport fetches taking over the terminal; these fetches now fail fast instead of asking
No entry names this #96858Worktree fetch leaves ssh reading keystrokes from the terminal Open
-p sessions leaving its tools available
Nothing to match on claude -p --permission-prompt-tool: a background subagent's permission request now goes to the prompt tool instead of being auto-denied
No entry names this claude mcp list and claude mcp get, and the not-found error of claude mcp remove, login and logout, printing line breaks and terminal escape sequences from MCP server names and values
Probably mcp-tool-call-stdio-check-and-secret-masking-in-mcp-get python3 -c, node -e) just because they contain =
No entry names this dontAsk mode: a fork now runs under its parent's permission mode and cannot exit plan mode
No entry names this #95155[BUG] Fork subagent performs write actions despite parent session being in plan mode Open
#95154[BUG] Fork subagent performs write actions despite parent session being in plan mode Closed
claude remote-control --help saying --[no-]chrome defaults to the machine's /chrome setting; spawned sessions keep Claude in Chrome off unless --chrome is passed
Probably sandbox-and-gateway-smaller-changes, headless-cli-argument-classification-list /remote-env reading only the newest 20 of an account's environments
No entry names this claude plugin install or /plugin putting it into an installed plugin's cache or data folder when their ids differ only in ., -, @ or (macOS, Windows) capitals; the install is now refused
Probably hint-for-bundled-mcp-servers-that-need-configuration, mcp-server-policy-checks-extended-to-plugin-provided-and-url, new-claude-plugin-configure-cli-command-with-values-stdi ANTHROPIC_AUTH_TOKEN against the Anthropic API never loading the organization's policy
Probably ssh-placeholder-credential-detection agent(), parallel() or pipeline() call that a workflow script awaits later, or not at all, being treated as an unhandled promise rejection, which could end a background session
Probably workflow-swallows-unhandled-promise-rejections some-daemon &) kept its output open; the hook now finishes shortly after its own process exits
No entry names this #92934Windows: synchronous command hooks wait for persistent descendants Closed
modelTimeoutException and serviceUnavailableException errors showing a raw JSON body instead of the error message
No entry names this /autofix-pr and /schedule saying the Claude GitHub App is not installed on a repository whose install status had not been checked yet
No entry names this /artifacts unlinking its file from the artifact, so publishing the same file again created a new artifact instead of updating it
Probably artifact-publish-tool-prompt-no-longer-lists-artifacts-hint Artifact allow rule ("don't ask again") letting the Artifact tool publish a file outside the working directories without asking; add the file's folder with --add-dir for the rule to cover it
Probably network-permission-dont-ask-again-can-persist-to-user-set /cost and SDK modelUsage reporting a turn under the wrong model when the server answered a refusal with a different fallback model than the client expected
No entry names this /ultrareview when the project folder briefly could not be read
Probably workflows-disable-setting-description-clarifies-scope /ultrareview on macOS and Linux failing to upload the working tree from a git worktree whose per-worktree config sets core.longpaths
Probably workflows-disable-setting-description-clarifies-scope /ultrareview uploads including uncommitted changes to credential files whose name has a colon before the extension, such as server:8443.key
Probably workflows-disable-setting-description-clarifies-scope /ultrareview uploads on macOS and Linux running slowly on some unusual file names, and their credential-file check missing file or folder names with many backup or editor marks
Probably workflows-disable-setting-description-clarifies-scope x or r in NORMAL mode no longer breaks a pasted-text placeholder at the end of the prompt
Nothing to match on .mcpb MCP server that still needs configuration: /plugin, the install message and claude plugin install now say so and point to Configure
Probably hint-for-bundled-mcp-servers-that-need-configuration, mcp-server-policy-checks-extended-to-plugin-provided-and-url, new-claude-plugin-configure-cli-command-with-values-stdi #95683[BUG] For marketplace installs the MCP bundle (.mcpb) user_config is never prompted for Open
/ultrareview refusing to upload a checkout on a Linux volume when a changed file's name has a colon or ends in a dot or space
Probably workflows-disable-setting-description-clarifies-scope CLAUDE_CODE_RESUME_INTERRUPTED_TURN re-running a turn that had ended at --max-turns
Probably remote-session-max-turns-is-passed-to-cloud-sessions-and-i, maxturns-validation-for-cloud-sessions-and-attach, headless-resume-of-interrupted-turn-orphaned-task-flush-is, max-turns-reported-as-lost, cloud-session-flag-table-maxturns-no-longer-unsupported-de /ultrareview uploading a linked worktree of a repository rooted at your home folder in some cases
Probably workflows-disable-setting-description-clarifies-scope claude agents to a background session waiting on a permission prompt sometimes approving the pending command
Probably resume-picker-now-offers-to-open-a-live-background-session claude attach, logs, stop, respawn and rm starting a new session with the command name as its prompt when options came before it, such as from a shell alias
Probably resume-picker-now-offers-to-open-a-live-background-session, resuming-a-session-that-is-running-in-the-background-can-ope, resuming-a-live-background-session-can-now-attach-to-it-and claude mcp list leaving out WebSocket (ws) MCP servers; each is now listed with its URL and health status
No entry names this claude mcp get showing no Type, Command, Args, or Environment for stdio servers whose config entry omits the type field
Probably mcp-tool-call-stdio-check-and-secret-masking-in-mcp-get .claude/settings.local.json allow rules being held back outside a git repository when git's trace2 output is configured
No entry names this /claude-api eval runner scaffold and report builder writing through a symlink or hard link planted at an output file
No entry names this /claude-api eval runner scaffold counting responses cut off at max_tokens in the score averages; they are now marked truncated and counted separately
No entry names this showing as literal text in the terminal when a reply uses it to indent text, such as row labels in a markdown table
Nothing to match on /clear or /compact
Probably idle-clear-hint-now-counts-from-other-sessions-turns /btw side question asked of a session hosted by an app such as Claude Desktop now sees the turn in progress, not only the last finished one
No entry names this ping stream event is now sent every 30 seconds on the Anthropic API, Claude Platform on AWS and gateways
Nothing to match on /resume and claude --resume on a session that is running in the background: they now open that session instead of refusing, and a prompt given with claude --resume <id> "prompt" is sent to it as its next turn
Probably update-refusal-message-names-the-two-directories, resume-of-a-live-session-now-hands-off-with-a-prompt, new-claude-desktop-launcher-for-claude-desktop, new-desktop-cli-option, resume-picker-now-offers-to-open-a-live-background-session, resuming-a-live-background-session-can-now-attach-to-it-and _meta['anthropic/alwaysLoad'] to false stays deferred when its --mcp-config, Agent SDK or plugin server is set to alwaysLoad
Probably claude-in-chrome-can-be-served-by-the-remote-session-host-ov, alwaysload-mcp-option-server-tools-can-opt-out-per-tool timeout with run_in_background, default 30 min, max 2 h); Claude is notified when one is stopped
Probably the-bash-tool-description-was-rewritten, the-bash-tool-description-in-the-command-security-review-pro, the-bash-tool-description-in-the-command-team-onboarding-pro, background-shell-commands-get-a-stop-deadline /ultrareview to run when disableWorkflows is on, unless the machine running the review has it set by its own administrator (MDM or the managed-settings file)
Probably workflows-disable-setting-description-clarifies-scope, workflows-kill-switch-claude-code-disable-workflows-and-dis ANTHROPIC_BASE_URL to use the 1M context window of models that have one (Opus 4.7+, Sonnet 5+, Fable); run /autocompact 200k if your gateway stops at 200K
No entry names this claude -p and Python Agent SDK sessions on third-party providers or with telemetry off to start in auto mode when no permission mode is configured, like interactive sessions; --permission-mode still overrides it
No entry names this widgets to be reserved in cloud sessions and on self-hosted runners: your own server under it, or a close spelling such as widgets_, no longer loads, so rename it
No entry names this /ultrareview on macOS and Linux to leave symbolic refs out when uploading a local checkout; a checkout whose current branch is a symbolic ref is now refused with an explanation
Probably workflows-disable-setting-description-clarifies-scope env to no longer set ALLUSERSPROFILE, SystemDrive, or the CommonProgramFiles variables; set them in user or managed settings instead
Probably windows-env-passthrough-list-extended, allusersprofile-added-to-an-env-allowlist-opus-4-max-token /tasks to fold background work Claude Code runs for itself under one "System tasks" row; press Enter on it to show those tasks
Probably background-tasks-dialog-collapses-self-managed-tasks-into-on /ultrareview on macOS and Linux to require git 2.31 or newer to upload a local repository; checkouts made with --separate-git-dir are now refused instead of being uploaded with an older method
Probably workflows-disable-setting-description-clarifies-scope /ultrareview uploads on macOS and Linux to send a partial clone as a working-tree snapshot on git 2.31 or newer, instead of falling back or refusing when git's version looked too old
Probably workflows-disable-setting-description-clarifies-scope /ultrareview uploads on macOS and Linux to refuse, instead of fetching, a partial clone missing some of its working tree's files on older git versions; a clone made without --filter uploads
Probably workflows-disable-setting-description-clarifies-scope claude mcp get to hide the command, arguments, and environment values of stdio MCP servers provided by plugins; variable names are still shown
Probably mcp-tool-call-stdio-check-and-secret-masking-in-mcp-get /claude-api so it can no longer be run from Remote Control clients
No entry names this /config chrome=true to direct you to the /config panel instead of enabling Claude in Chrome by default; /config chrome=false still turns it off when it was on
No entry names this CLAUDE_CODE_RESUME_INTERRUPTED_TURN set, even with Continue After Reload off
Probably headless-resume-of-interrupted-turn-orphaned-task-flush-is CLAUDE_CODE_SUBAGENT_MODEL_FORCE or an agent's own model)
No entry names this .claude/settings.json turns on
Probably project-settings-can-no-longer-set-some-keys MCP_DISCOVERY_CACHE=1, when set in your cloud environment's variables rather than a settings file, to reuse your connectors' tool lists after a session restart; other MCP servers are no longer cached and connect at startup
Probably mcp-discovery-cache-for-ccr-dynamic-http-servers A model matched these bullets to the GitHub issues they fix, so a link can be wrong.
1 of 27 tool descriptions changed. 1 of 25 tool schemas changed. The appended system-reminder blocks moved: 1 line added.
Claude Code, interactive mode
401 documentation changes were recorded within 24 hours either side of this release, nearest first. The closest 12 are below. They're here because they happened near this release in time. That's not a claim that this release caused the edit, or that the page documents anything in it.
The 87 literal strings found in the bundle, with the number of entries that name each one. Picking one searches for it. A name is here because this build's code mentions it, which is not the same as it working or being finished.
What's wrong with this entry?